This invention relates to transceiver circuits and, in particular, to a half-duplex transceiver using a light emitting diode (LED).
In the past, optical transceiver circuits have used separate emitters and detectors and a pair of optical fibers. In systems where substantial lengths of optical fiber is used, directional couplers are employed to enable use of a single fiber. In either event, the cost of such systems is substantial.
There are many applications in which two way communication is desired over relatively short distances at low cost; for example, within vehicles, homes, factories, and offices. In these applications, cost rather than optical performance becomes the prime consideration, particularly as the number of communication paths increases. Optical performance is not a prime consideration since the relatively short distance, eg. less than one kilometer, does not require high output power, extremely low loss cable, or high sensitivity detectors.
In such applications, it would also be advantageous to provide communication over a single fiber, particularly where it is desired to improve an existing system by substituting two-way communication for one-way communication or where one wants to double the number of existing two-way channels.
In view of the foregoing, it is therefore an object of the present invention to provide a low cost, optical transceiver.
Another object of the present invention is to provide an optical transceiver using a single device for both emission and detection.
A further object of the present invention is to provide a half-duplex optical transceiver.